Motor.



' J. T. McGRATH.

MOTOR.

APPLIU-AI'ION rmm JULY 16, 1903.

PATENTED APR. 19, 1904.

K0 MODEL.

UNITED STATES Patented April 19, 1904.

PATENT OFFICE.

MOTOR.

SPECIFICATION forming part of Letters Patent No. 757,485, dated April 19, 1904.

. Application filed m 16, 1903.

To all whom, it may concern: A

Be it known that I, JOHN THOMAS McGRA'rH, of the city of Port Huron, in the county of St. Clair, in the State of Michigan, have invented certain new and useful Improvements in M- gear which operates the machine to be driven;

- section on the line a 5, Fig, 1.

and it consists, essentially, of a substantially triangular casing with a suitable orifice to admit the air underpressure, such casing being hermetically sealed, so as'to retain the air under pressure, and being provided, preferably, with two cylinders having their rods connected to a crank-wheel, a sliding valve supported on suitable linksat the heads of thecylinders, and a slide-valve for controlling the admission and exhaust of the air from the cylinders, all being arranged as hereinafter more particularly explained.

Figure 1 is a side elevation showing the cylinders and slide-Valves at the head thereof in section. Fig. i 2 is an enlarged longitudinal Fig. 3 is 9. Iongitudi-nal section onthe line 0 d, Fig. 1. Fig. 4 is a sectional plan on the line 6 f, Fig. 1.

In the drawings like characters of reference indicate corresponding parts in each figure.

A is the side of the casing, which is of polygonal form and having a suitable cover-plate A and inlet-orifice A Y B is the main shaft, and O the crank-wheel thereof.

- D D are cylinders. Each cylinder Dis pro-] vided with a piston (Z,- whichis connected by a piston-rod d to the wrist-pin d on the crankwheel. Each cylinder D is also provided with a short passage-way 2, leading to the top end of the piston, and a long passage-way 3, leading to the bottom end of the piston. The pas sage-ways 2 and 3 converge at the top of the cylinder, as indicated. p

E is a pin, the reduced threaded inner end 6 of which fits into a corresponding socket A in the boss A in the casing A. The outer smart. 165,858. (in model.)

I end of the pin is provided with a nut e, and

the pin intermediate of its length is provided with an annular recess 6 e is a spring encircling the pin E and extending between the cylinder and the coverplate A. The pin E forms the point upon which the cylinder D oscillates.

F is a slide-valve which is connected by the link f to a pin f forming part of the casing. The slide-valve is held upon the seat on the top of the cylinder by means of the air-pressure within the casing, and such slide-valve is provided with the side ports 4 and 5 and central port 6.

G and G are passage-ways formed in the casing A on the back plate. The passageways G and G cross each other without con1 municating with each other at the point of crossing, the casting being so formed. The passage-way G at the left hand leads to ports 4 and 5 in the slide-valve and at the right hand leads to the port 9 in the cylinder, and the passage-way G at the left hand leads to the port 9 in the cylinder and at the right hand to the ports 4 and 5 in the slide-valve. In each case where the passage-way G or G communicates with the slide-valve it passes into a passage-way 7, which communicates by. a passage-way 7, as indicated by dotted lines, to the ports 4 and 5, which communicate with the ports 3 and 2, respectively,.in the cylinder. In each case where the passage-way G or G communicates with the cylinder it passes into a port 9, thence into the annular recess 6 which communicates with the port 8,"which in turn communicates with the port 6 in the slide-valve, which communicates alternately with the ports 2 and 3 in the cylinder;

. Intermediate of the length of the passageways G and G, I provide the controlling slidevalve H, which is provided with a cavity h, which is designed to straddle the passage-way G and exhaust-port 10 or the passage-way G and exhaust-port 10. The slide-valve H is supported in suitable guideways It. The slide-valve is manipulated by means of an arm 11, fixed on a pin 12, which is operated by. a suitable lever. As will hereinafter appear, the position into which the slide-valve H is thrown will regulate the direction of rotation of the shaft B.

It will of course be understood that either of the passage-ways Gr or G will be open to the interior of the casing, and in'the drawings in Fig. 3 I show the passage-way G open to the interior of the casing'that is to say, the

machine in an upright position and designed to be operated by the pressure of the air passing through the passage-way G.

Having now described the construction of my invention, I shall proceed to point out the mode of operation of the same. As the air passes through the passage way G to the right it necessarily passes into the cavity 7, thence into the port 4:, which communicates with the port 3, and passes into the interior of the cylinder, forcing the piston d upwardly and the crank-wheel in the direction indicated by arrow. At the same time the air passes through the passage-way G to the left into the port 9, thence successively through the recess 6 port 8 into the cavity 6, thence (when the cylinder further oscillates) into the port 3 of the companion cylinder, thereby serving to force the piston d upwardly and pull the crank-wheel (J, and consequently rotate the shaft B, in the direction indicated byarrow. The exhaust, however, passes outwardly through the then exhaust passage-way G by a course exactly the reverse of that already described, thence into the cavity h in the controlling slide-valve H and exhaust passageway 10. When the slide-valve H is placed. so as to cover the exhaust passage-way 10 and passage-way G, of course the direction of rotation is reversed.

It is to be understood that although I have described my invention as being adapted to be driven by compressed air it might be driven by any other suitable fluidsuch as gas, water, steam, or the likethough air is the preferable source of power. It is also to be understood that Ido not wish to limit myself to the exact details of construction as herein shown and described; but I wish to be able to vary the construction of device within the scope of ordinary mechanical skill.

What I claim as my invention is- 1. In an air-motor, the combination with the casing, main shaft and crank-wheel, of the oscillating cylinders provided with passageways leading from each end thereof to the top thereof, coacting slide-valves supported on links and passage-ways leading to the slidevalves and cylinder passage-ways as and for the purpose specified.

2. In adevice of the class described, the combination with an air-tight casing, of the main shaft, a crank-wheel secured thereto, a pair of oscillating cylinders located inthe casing, the piston rods operatively connected to the crank-wheel, the slide-valves coacting with the cylinders, inlet and exhaust openings for the casing, supply-passages communicating between the inside of the casing and the cylinders and slide-valves and exhaust-passages communicating between the exhaust-outlet and the cylinders and slide-valves as and for the purpose specified.

3. In a device of the class described, the combination with a suitable air-tight casing, of

the main shaft, the crank-wheel secured thereto, a pair of oscillating cylinders located in such casing, the piston-rods operatively attached to the crank-wheel, the slide-valves coacting with the cylinders, inlet and exhaust openings for the casing, inlet-passages communicating between the inside of the casing and the cylinders and slide-valves, and exhaust-passages communicating between the exhaust-outlet and the cylinders and slidevalves, and a reversing-valve as and for the purpose specified.

4. In a device of the class described, the combination with the casing, the main shaft and crank-wheel, of the oscillating cylinders-and their pistons and the piston-rods connected to the crank-wheel, said cylinders having passage-ways leading from each end thereof to the top thereof, coacting slide-valves supported on links, a pair of passage-ways one communicating on its right with the passages of the right-hand cylinder and on its left with the valve of the left-hand cylinder, and the other passage-way communicating on its right with the slidevalve of the right-hand cylinder and on its left with the passage-way of the left-hand cylinder and means for connecting either one of said passages with the interior of the casing and the other with the exhaustopening as and for the purpose specified.

5. In a device of theclass described, the combination with the casing having the supply and exhaust passage-ways, of the main shaft and crank-wheel, the oscillating cylinders and their pistons connected to the crank-wheel, the coacting slide-valves and their link connections with the casing, said slide-valves being adapted to slide on valve-seats on the tops of the cylinders and said slide-valves and cylinders having sliding contact with valve-seats formed integral with the casing, shafts upon which the cylinders are pivotally mounted, springs encircling said shafts and adapted to force the cylinders against the casing valveseats, said cylinders and slide-valves having suitable ports and passages to form communication botween the inlet and exhaust passages and the portions of the cylinders above and below the pistons alternately as and for the purpose specified.

JOHN THOMAS MOGRATH.

Witnesses:

THOMAS J. TAYLOR, JOHN C. PAToN. 

